February 2009 arXiv papers — page 11

Bianca L. Cerchiai, Sergio Ferrara, Alessio Marrani, Bruno Zumino

We consider the Bekenstein-Hawking entropy-area formula in four dimensional extended ungauged supergravity and its electric-magnetic duality property. Symmetries of both "large" and "small" extremal black holes are considered, as well as the ADM mass formula for N=4 and N=8 supergravity, preserving different fraction of supersymmetry. The int

Luiz. C. L. Botelho

By means of the Minlos Theorem on support of cylindrical measures on vectorial topological spaces, we present several results on the rigorous definitions of Euclidean path integrals and applications to some problems on non-linear diffusion, nonlinear wave propagations and covariant Polyakov"s path Integrals yielding news results on the subject as well.

Adi Zitrin, Tom Broadhurst, Keiichi Umetsu, Dan Coe

We present an improved strong-lensing analysis of Cl0024+1654 ($z$=0.39) using deep HST/ACS/NIC3 images, based on 33 multiply-lensed images of 11 background galaxies. These are found with a model that assumes mass approximately traces light, with a low order expansion to allow for flexibility on large scales. The model is constrained initially by the well kn

Massimo Rontani, L. J. Sham

Technological advances allow for tunable lateral confinement of cold dipolar excitons in coupled quantum wells. We consider theoretically the Josephson effect between exciton condensates in two traps separated by a weak link. The flow of the exciton supercurrent is driven by the dipole energy difference between the traps. The Josephson oscillations may be ob

Bjorn Poonen

There is an algorithm that takes as input a global field k and produces a curve over k violating the local-global principle. Also, given a global field k and a nonnegative integer n, one can effectively construct a curve X over k such that #X(k)=n and X has points over every completion of k.

R. M. Rajapakse, T. Bragdon, A. M. Rey, T. Calarco

We model single photon nonlinearities resulting from the dipole-dipole interactions of cold polar molecules. We propose utilizing ``dark state polaritons'' to effectively couple photon and molecular states; through this framework, coherent control of the nonlinearity can be expressed and potentially used in an optical quantum computation architecture

Bjorn Poonen

For each number field k, the Bombieri-Lang conjecture for k-rational points on surfaces of general type implies the existence of a polynomial f(x,y) in k[x,y] inducing an injection k x k --> k.

Frederic Jugeau

This note focuses on the large-N behaviour of the Hard Wall model of QCD and clarifies the AdS/QCD dictionary formulated on the basis of the AdS/CFT correspondence. It is shown how short-distance studies performed in the framework of the AdS/QCD Soft Wall model allow one to determine unambiguously the chiral symmetry breaking function in the Hard Wall model.

S. S. Afonin

The problem of obtaining the Regge-like behaviour for meson mass spectrum in the hard-wall AdS/QCD models is addressed. We show that the problem can be solved by a simple incorporation of the effects of local vacuum condensates into such models. The slope of trajectories turns out to be determined by the local condensate of dimension~2 that is absent in the

Laurent Doyen, Jean-Francois Raskin

We propose and evaluate antichain algorithms to solve the universality and language inclusion problems for nondeterministic Buechi automata, and the emptiness problem for alternating Buechi automata. To obtain those algorithms, we establish the existence of simulation pre-orders that can be exploited to efficiently evaluate fixed points on the automata defin

Fei Han, Xiyu Zhu, Ying Jia, Lei Fang

By substituting the Fe with the 5d-transition metal Ir in SrFe2As2, we have successfully synthesized the superconductor SrFe2-xIrxAs2 with Tc = 22.3 K at x = 0.5. X-ray diffraction indicates that the material has formed the ThCr2Si2-type structure with a space group I4/mmm. The temperature dependence of resistivity and dc magnetization both reveal sharp supe

Paolo Aschieri, Leonardo Castellani

We present a noncommutative D=3, N=1 supergravity, invariant under diffeomorphisms, local U(1,1) noncommutative \star-gauge transformations and local \star-supersymmetry. Its commutative limit is the usual D=3 pure supergravity, without extra fields. A noncommutative deformation of D=4, N=1 supergravity is also obtained, reducing to the usual simple supergra

Marco Baiesi, Christian Maes, Bram Wynants

A generalized fluctuation-response relation is found for thermal systems driven out of equilibrium. Its derivation is independent of many details of the dynamics, which is only required to be first-order. The result gives a correction to the equilibrium fluctuation-dissipation theorem, in terms of the correlation between observable and excess in dynamical ac

Z. Bern, J. J. M. Carrasco, H. Johansson

In this lecture we summarize recent calculations pointing to the possible ultraviolet finiteness of N = 8 supergravity in four dimensions. We outline the modern unitarity method, which enables multiloop calculations in this theory and allows us to exploit a remarkable relation between tree-level gravity and gauge-theory amplitudes. We also describe a link be

Dieter Mayer, Tobias Mühlenbruch

We discuss the nearest lambda_q--multiple continued fractions and their duals for lambda_q = 2 cos(pi/q) which are closely related to the Hecke triangle groups G_q, q=3,4,... . They have been introduced in the case q=3 by Hurwitz and for even q by Nakada. These continued fractions are generated by interval maps f_q respectively f_q^* which are conjugate to s

R. Feyerherm, E. Dudzik, A. U. B. Wolter, S. Valencia

X-ray resonant magnetic scattering studies of rare earth magnetic ordering were performed on perovskite manganites RMnO3 (R = Dy, Gd) in an applied magnetic field. The data reveal that the field-induced three-fold polarization enhancement for H || a (H approx. 20 kOe) observed in DyMnO3 below 6.5 K is due to a re-emergence of the Mn-induced Dy spin order wit

Ki-Myeong Lee, Sangmin Lee, Sungjay Lee

We investigate the low energy physics of particles in the symmetric phase of the N=6 mass-deformed ABJM theory in terms of the superconformal nonrelativistic field theory with 14 supercharges. They describe the certain kind of excitations on M2 branes in the background of external four-form flux. We study the nonrelativistic superconformal algebra and their

H. Hergert, R. Roth

In this first in a series of articles, we apply effective interactions derived by the Unitary Correlation Operator Method (UCOM) to the description of open-shell nuclei, using a self-consistent Hartree-Fock-Bogoliubov framework to account for pairing correlations. To disentangle the particle-hole and particle-particle channels and assess the pairing properti

C. Di Fidio, W. Vogel

It is shown that entanglement, which is a quantum correlation property of at least two subsystems, is imprinted in the mode structure of a single photon. The photon, which is emitted by two coupled cavities, carries the information on the concurrence of the two intracavity fields. This can be useful for recording the entanglement dynamics of two cavity field

Eric Plaza

This work proposes a method for the two-dimensional simulation of Brownian particles in a fluid with restrictions. The method is based on simple numerical rules between two matrices. One of the matrix represent the identification of all particles over which are adapted statistics rules for particles movement, the results are mapped over other matrix which re

C. Barbieri, M. Hjorth-Jensen

The single-particle spectral function of 56Ni has been computed within the framework of self-consistent Green's functions theory. The Faddeev random phase approximation method and the G-matrix technique are used to account for the effects of long- and short-range physics on the spectral distribution. Large scale calculations have been performed in spaces

M. Feito, J. P. Baltanas, F. J. Cao

We investigate the different regimes that emerge when a periodic driving force, the rocking force, acts on a collective feedback flashing ratchet. The interplay of the rocking and the feedback control gives a rich dynamics with different regimes presenting several unexpected novel features. In particular, we show that for both the one-particle ratchet and th

K. Xia, J. Evers

Ground state cooling of a nanomechanical resonator coupled to a superconducting flux qubit is discussed. We show that by inducing quantum interference to cancel detrimental carrier excitations, ground state cooling becomes possible in the weak-confinement or non-resolved regime. The qubit is modelled as a three-level system in lambda configuration, and the d

Michael Hauer, Giorgio Torrieri, Spencer Wheaton

Multiplicity fluctuations and correlations are calculated within thermalized relativistic ideal quantum gases. These are shown to be sensitive to the choice of statistical ensemble as well as to the choice of acceptance window in momentum space. It is furthermore shown that global conservation laws introduce non-trivial correlations between disconnected regi

J. -F. Mercure, S. K. Goh, E. C. T. O'Farrell, R. S. Perry

We report measurements of quantum oscillations detected in the putative nematic phase of Sr3Ru2O7. Significant improvements in sample purity enabled the resolution of small amplitude dHvA oscillations between two first order metamagnetic transitions delimiting the phase. Two distinct frequencies were observed, and their amplitudes follow the normal Lifshitz-

M. J. Reid, A. Brunthaler, K. M. Menten, L. Loinard

Recent advances with the VLBA have resulted in ~10 micro-arcsec astrometry for compact sources in external galaxies, and measurement of the proper motion of Local Group galaxies has been demonstrated. With improved telescopes and equipment, we could greatly improve upon and expand these measurements, including a measurement of the proper motion of the Androm

Wojciech Borkowski

In this paper I describe a cellular automaton model of a multi-species ecosystem, suitable for the study of emergent properties of macroevolution. Unlike majority of ecological models, the number of coexisting species is not fixed. Starting from one common ancestor they appear by "mutations" of existent species, and then survive or extinct depending

Ehsan Noruzifar, Martin Oettel

We study the effective interaction between two ellipsoidal particles at the interface of two fluid phases which are mediated by thermal fluctuations of the interface. In this system the restriction of the long--ranged interface fluctuations by particles gives rise to fluctuation--induced forces which are equivalent to interactions of Casimir type and which a

M. J. Reid, K. M. Menten, A. Brunthaler, G. A. Moellenbrock

Recent advances in radio astrometry with the VLBA have resulted in near micro-arcsecond accurate trigonometric parallax and proper motion measurements for masers in star forming regions. We are now poised to directly measure the full 3-dimensional locations and motions of every massive star forming region in the Milky Way and for the first time to map its sp

Remo Garattini

We compute the black hole entropy in the context of the Modified Dispersion Relations using the brick wall model. An explicit dependence of the radial coordinate approaching the horizon is shown to analyze the behavior of the divergence. We find that, due to the modification of the density of states, the brick wall can be eliminated. By assuming a specific f

Benedetta Noris, Susanna Terracini

In this paper we consider a stationary Schroedinger operator in the plane, in presence of a magnetic field of Aharonov-Bohm type with semi-integer circulation. We analyze the nodal regions for a class of solutions such that the nodal set consists of regular arcs, connecting the singular points with the boundary. In case of one magnetic pole, which is free to

Michael A. Buice, Jack D. Cowan, Carson C. Chow

Population rate or activity equations are the foundation of a common approach to modeling for neural networks. These equations provide mean field dynamics for the firing rate or activity of neurons within a network given some connectivity. The shortcoming of these equations is that they take into account only the average firing rate while leaving out higher

Stoil Donev, Maria Tashkova

This paper aims to review our recent results on exploring the capabilities of non-quantum field theory as a possible tool for describing single photon-like objects, considered as massless time-stable spatially finite physical entities with compatible translational-rotational dynamical structure. The main idea is to interpret the local physical interaction as

Grzegorz Wilk, Zbigniew Wlodarczyk

We investigate the multiplicity fluctuations observed in high-energy nuclear collisions attributing them to intrinsic fluctuations of temperature of the hadronizing system formed in such processes. To account for these fluctuations we replace the usual Boltzmann-Gibbs (BG) statistics by the non-extensive Tsallis statistics characterized by the nonextensivity

A. Tiribocchi, N. Stella, G. Gonnella, A. Lamura

A hybrid lattice Boltzmann method (LBM) for binary mixtures based on the free-energy approach is proposed. Non-ideal terms of the pressure tensor are included as a body force in the LBM kinetic equations, used to simulate the continuity and Navier-Stokes equations. The convection-diffusion equation is studied by finite difference methods. Differential operat

Ivan Damgaard, Serge Fehr, Carolin Lunemann, Louis Salvail

We consider two-party quantum protocols starting with a transmission of some random BB84 qubits followed by classical messages. We show a general "compiler" improving the security of such protocols: if the original protocol is secure against an "almost honest" adversary, then the compiled protocol is secure against an arbitrary computationall

Alice Mikikits-Leitner, Gerald Teschl

We investigate trace formulas for one-dimensional Schroedinger operators which are trace class perturbations of quasi-periodic finite-gap operators using Krein's spectral shift theory. In particular, we establish the conserved quantities for the solutions of the Korteweg-de Vries hierarchy in this class and relate them to the reflection coefficients via

Mohsen Alishahiha, Reza Fareghbal, Amir E. Mosaffa, Shahin Rouhani

We show that the asymptotic symmetry algebra of geometries with Schrodinger isometry in any dimension is an infinite dimensional algebra containing one copy of Virasoro algebra. It is compatible with the fact that the corresponding geometries are dual to non-relativistic CFTs whose symmetry algebra is the Schrodinger algebra which admits an extension to an i

Pablo Minces

We consider a scalar field theory in AdS_{d+1}, and introduce a formalism on surfaces at equal values of the radial coordinate. In particular, we define the corresponding conjugate momentum. We compute the Noether currents for isometries in the bulk, and perform the asymptotic limit on the corresponding charges. We then introduce Poisson brackets at the bord

Ilarion V. Melnikov

We study the topological heterotic ring in (0,2) Landau-Ginzburg models without a (2,2) locus. The ring elements correspond to elements of the Koszul cohomology groups associated to a zero-dimensional ideal in a polynomial ring, and the computation of half-twisted genus zero correlators reduces to a map from the first non-trivial Koszul cohomology group to c

M. J. Reid, K. M. Menten, X. W. Zheng, A. Brunthaler

We are using the VLBA and the Japanese VERA project to measure trigonometric parallaxes and proper motions of masers found in high-mass star-forming regions across the Milky Way. Early results from 18 sources locate several spiral arms. The Perseus spiral arm has a pitch angle of 16 +/- 3 degrees, which favors four rather than two spiral arms for the Galaxy.

A. V. Paraskevov

This is an extended version of the Comment that contains the criticism against an applicability of the diffusive transport model for the explanation of the ring-shaped spatial pattern formation in the exciton photoluminescence for the GaAs/AlGaAs double quantum wells [Phys. Rev. Lett. 92, 117404 (2004)]. The model has been used in other similar papers publis

Simone Pigolotti, Massimo Cencini

The general tendency for species number (S) to increase with sampled area (A) constitutes one of the most robust empirical laws of ecology, quantified by species-area relationships (SAR). In many ecosystems, SAR curves display a power-law dependence, $S\propto A^z$. The exponent $z$ is always less than one but shows significant variation in different ecosyst

Daniele Oriti

We present a new Group Field Theory for 4d quantum gravity. It incorporates the constraints that give gravity from BF theory, and has quantum amplitudes with the explicit form of simplicial path integrals for 1st order gravity. The geometric interpretation of the variables and of the contributions to the quantum amplitudes is manifest. This allows a direct l

V. Gogokhia, M. Vasúth

The effective potential approach for composite operators has been generalized to non-zero temperatures in order to derive equation of state for the pure SU(3) Yang-Mills fields from first principles. In the absence of external sources it is nothing but the vacuum energy density. The key element of this derivation was an introduction of the temperature depend

Michael V. Bebronne, Peter G. Tinyakov

The static vacuum spherically symmetric solutions in massive gravity are obtained both analytically and numerically. The solutions depend on two parameters (integration constants): the mass M (or, equivalently, the Schwarzschild radius), and an additional parameter, the "scalar charge" S. At zero value of S and positive mass the standard Schwarzschil

S. N. Gninenko

The anomaly in the low energy distribution of quasi-elastic neutrino events reported by the MiniBooNE collaboration is discussed. We show that the observed excess of electron-like events could originate from the production and decay of a heavy neutrino ($ν_h$) in the MiniBooNE detector. The $ν_h$ is created by mixing in $ν_μ$ neutral-current interactions and

Italo Guarneri

It is proven that none of the bands in the quasi-energy spectrum of the Quantum Kicked Rotor is flat at any primitive resonance of any order. Perturbative estimates of bandwidths at small kick strength are established for the case of primitive resonances of prime order. Different bands scale with different powers of the kick strength, due to degeneracies in

V. P. S. Awana, Arpita Vajpayee, Anand Pal, Monika Mudgel

We report superconductivity in the SmFe0.9Co0.1AsO system being prepared by most easy and versatile single step solid-state reaction route. The parent compound SmFeAsO is non-superconducting but shows the spin density wave (SDW) like antiferromagnetic ordering at around 140K. To destroy the antiferromagnetic ordering and to induce the superconductivity in th

V. P. S. Awana, Jagdish Kumar Bains, G. S. Okram, Ajay Soni

Temperature dependence of thermoelectric power S(T) of three differently processed Bi2Sr2CaCu2O8 (Bi2212) samples, viz. as-processed melt quenched (Bi2212-MQ), 6000C N2-annealed (Bi2212-N2) and 6000C O2-annealed (Bi2212-O2) is reported here. All the samples possess single-phase character and their superconducting transition temperatures (TcR=0) are 85 K, 90

Alain Pumir, Sitabhra Sinha, S. Sridhar, Mederic Argentina

A free vortex in excitable media can be displaced and removed by a wave-train. However, simple physical arguments suggest that vortices anchored to large inexcitable obstacles cannot be removed similarly. We show that unpinning of vortices attached to obstacles smaller than the core radius of the free vortex is possible through pacing. The wave-train frequen

Goncalo Tabuada

In this paper we pursue the study of spectral categories initiated in [26]. More precisely, we construct the Universal matrix invariant of spectral categories, i.e. a functor U with values in an additive category Add, which inverts the Morita equivalences, satisfies matrix invariance, and is universal with respect to these two properties. For example, the al

D. A. Trifonov, B. A. Nikolov, I. M. Mladenov

It is shown that the Bohm equations for the phase $S$ and squared modulus $ρ$ of the quantum mechanical wave function can be derived from the classical ensemble equations admiting an aditional momentum $p_s$ of the form proportional to the osmotic velocity in the Nelson stochastic mechanics and using the variational principle with appropriate change of varia

Takeshi Morita

We discuss an ambiguity of the derivation of the Hawking radiation through the gravitational anomaly method and propose modifications of this method such that it reproduces the correct thermal fluxes. In this modified gravitational anomaly method, we employ the two-dimensional conformal field theory technique.

Alina Ostafe, Igor Shparlinski

In this paper we study a class of dynamical systems generated by iterations of multivariate polynomials and estimate the degreegrowth of these iterations. We use these estimates to bound exponential sums along the orbits of these dynamical systems and show that they admit much stronger estimates than in the general case and thus can be of use for pseudorando

Lars Eirik Danielsen, Matthew G. Parker

We show that (n,2^n) additive codes over GF(4) can be represented as directed graphs. This generalizes earlier results on self-dual additive codes over GF(4), which correspond to undirected graphs. Graph representation reduces the complexity of code classification, and enables us to classify additive (n,2^n) codes over GF(4) of length up to 7. From this we a

Yu-Shen Liu, Yi-Ren Chen, Yu-Chang Chen

Using first-principles approaches, this study investigated the efficiency of energy conversion in nanojunctions, described by the thermoelectric figure of merit $ZT$. We obtained the qualitative and quantitative descriptions for the dependence of $ZT$ on temperatures and lengths. A characteristic temperature: $T_{0}= \sqrt{β/γ(l)}$ was observed. When $T\ll T

Folkmar Bornemann

We give a short, operator-theoretic proof of the asymptotic independence (including a first correction term) of the minimal and maximal eigenvalue of the n \times n Gaussian Unitary Ensemble in the large matrix limit n \to \infty. This is done by representing the joint probability distribution of the extreme eigenvalues as the Fredholm determinant of an oper

Sabyasachi Mukhopadhyay, Sisir Roy, Sourabh Bhattacharya

Recent technological advances have led to a flood of new data on cosmology rich in information about the formation and evolution of the universe, e.g., the data collected in Sloan Digital Sky Survey (SDSS) for more than 200 million objects. The analyses of such data demand cutting edge statistical technologies. Here, we have used the concept of mixture model

Masao Jinzenji

In this paper, we directly derive generalized mirror transformation of projective hypersurfaces up to degree 3 genus 0 Gromov-Witten invariants by comparing Kontsevich localization formula with residue integral representation of the virtual structure constants. We can easily generalize our method for rational curves of arbitrary degree except for combinatori

Yuya Dan

One is expressed as the sum of the reciprocals of a certain set of integers. We give an elegant proof to the fact applying the polynomial theorem and basic calculus.

Olivier Brunat, Jean-Baptiste Gramain

In this note, we construct a 2-basic set of the alternating group \A_n. To do this, we construct a 2-basic set of the symmetric group \sym_n with an additional property, such that its restriction to \A_n is a 2-basic set. We adapt here a method developed in \cite{BrGr} for the case when the characteristic is odd. One of the main tools is the generalized perf

J. C. Martinez-Oliveros, A. -C. Donea

Dynamical changes in the solar corona have proven to be very important in inducing seismic waves into the photosphere. Different mechanisms for their generation have been proposed. In this work, we explore the magnetic field forces as plausible mechanisms to generate sunquakes as proposed by Hudson, Fisher and Welsch. We present a spatial and temporal analys

James McBride, Onsi Fakhouri, Chung-Pei Ma

We use the extensive catalog of dark matter haloes from the Millennium simulation to investigate the statistics of the mass accretion histories (MAHs) and accretion rates of ~500,000 haloes from redshift z=0 to 6. We find only about 25% of the haloes to have MAHs that are well described by a 1-parameter exponential form. For the rest of the haloes, between 2

Erik Eriksson, Henrik Johannesson

We study the reduced fidelity between local states of lattice systems exhibiting topological order. By exploiting mappings to spin models with classical order, we are able to analytically extract the scaling behavior of the reduced fidelity at the corresponding quantum phase transitions out of the topologically ordered phases. Our results suggest that the re

Xiaoyu Hu, Jason Miller, Yuval Peres

Let $U\subseteq\mathbf{C}$ be a bounded domain with smooth boundary and let $F$ be an instance of the continuum Gaussian free field on $U$ with respect to the Dirichlet inner product $\int_U\nabla f(x)\cdot \nabla g(x)\,dx$. The set $T(a;U)$ of $a$-thick points of $F$ consists of those $z\in U$ such that the average of $F$ on a disk of radius $r$ centered at

Zekeriya Uykan

In this paper, we present and analyse two Hopfield-like nonlinear networks, in continuous-time and discrete-time respectively. The proposed network is based on an autonomous linear system with a symmetric weight matrix, which is designed to be unstable, and a nonlinear function stabilizing the whole network thanks to a manipulated state variable called``ulti

Zhiqin Lu, Michael R. Douglas

In this paper, we proved the Gauss-Bonnet-Chern theorem on moduli space of polarized Kahler manifolds. Using our results, we proved the rationality of the Chern-Weil forms (with respect to the Weil-Petersson metric) on CY moduli. As an application in physics, by the Ashok-Douglas theory, counting the number of flux compactifications of the type IIb string on

Peter Hall, Jiashun Jin

Higher criticism is a method for detecting signals that are both sparse and weak. Although first proposed in cases where the noise variables are independent, higher criticism also has reasonable performance in settings where those variables are correlated. In this paper we show that, by exploiting the nature of the correlation, performance can be improved by

Mauricio Martinez, Michael Strickland

We show that by requiring positivity of the longitudinal pressure it is possible to constrain the initial conditions one can use in 2nd-order viscous hydrodynamical simulations of ultrarelativistic heavy-ion collisions. We demonstrate this explicitly for 0+1 dimensional viscous hydrodynamics and discuss how the constraint extends to higher dimensions. Additi

Stefano Cardanobile, Delio Mugnolo

We investigate symmetry properties of vector-valued diffusion and Schrödinger equations. For a separable Hilbert space $H$ we characterize the subspaces of $L^2(Ω, H)$ that are local (i.e., defined pointwise) and discuss the issue of their invariance under the time evolution of the differential equation. In this context, the possibility of a connection betwe

T. Imai, K. Ahilan, F. L. Ning, T. M. McQueen

Unlike the parent phases of the iron-arsenide high Tc superconductors, undoped FeSe is not magnetically ordered and exhibits superconductivity with Tc~9K. Equally surprising is the fact that applied pressure dramatically enhances the modest Tc to ~37K. We investigate the electronic properties of FeSe using 77Se NMR to search for the key to the superconductin

Pavel Stransky, Petr Hruska, Pavel Cejnar

This is a continuation of our preceding paper devoted to signatures of quantum chaos in the geometric collective model of atomic nuclei. We apply the method by Peres to study ordered and disordered patterns in quantum spectra drawn as lattices in the plane of energy vs. average of a chosen observable. A good qualitative agreement with standard measures of ch

M. Vigelius, A. Melatos

We compute the continuous part of the ideal-magnetohydrodynamic (ideal-MHD) frequency spectrum of a polar mountain produced by magnetic burial on an accreting neutron star. Applying the formalism developed by Hellsten & Spies (1979), extended to include gravity, we solve the singular eigenvalue problem subject to line-tying boundary conditions. This spectrum

Yi Ni

If a 3--manifold $Y$ contains a non-separating sphere, then some twisted Heegaard Floer homology of $Y$ is zero. This simple fact allows us to prove several results about Dehn surgery on knots in such manifolds. Similar results have been proved for knots in $L$--spaces.

C. M. Hull, R. A. Reid-Edwards

String backgrounds with a local torus fibration such as T-folds are naturally formulated in a doubled formalism in which the torus fibres are doubled to include dual coordinates conjugate to winding number. Here we formulate and explore a generalisation of this construction in which all coordinates are doubled, so that the doubled space is a twisted torus, i

Kristoffer A. Eriksen, David Arnett, Donald W. McCarthy, Patrick Young

We present new reddening measurements towards the young supernova remnant Cassiopeia A, using two techniques not previously applied to this object. Our observations of the near-infrared [Fe II] 1.257 micron and 1.644 micron lines show the extinction to be highly variable across the remnant, increasing towards the west and the south, consistent with previous

Katherine A. Kornei, Nate McCrady

We present observations of a massive star cluster near the nuclear region of the nearby starburst galaxy NGC 253. The peak of near-infrared emission, which is spatially separated by 4" from the kinematic center of the galaxy, is coincident with a super star cluster whose properties we examine with low-resolution (R ~ 1,200) infrared CTIO spectroscopy and opt

Pedro Caro, Petri Ola, Mikko Salo

We prove a uniqueness theorem for an inverse boundary value problem for the Maxwell system with boundary data assumed known only in part of the bound- ary. We assume that the inaccessible part of the boundary is either part of a plane, or part of a sphere. This work generalizes the results obtained by Isakov for the Schrödinger equation to Maxwell equations.

Simon O'Toole, C. G. Tinney, R. Paul Butler, Hugh R. A. Jones

Precision Doppler measurements from an intensive 48 night "Rocky Planet Search" observing campaign on the Anglo-Australian Telescope (AAT) have revealed the presence of a low-mass exoplanet orbiting the G1 dwarf HD16417. Subsequent Doppler observations with the AAT, as well as independent observations obtained by the Keck Planet Search, have confirmed this i

G. L. Klimchitskaya, U. Mohideen, V. M. Mostepanenko

The physical origin of the Casimir force is connected with the existence of zero-point and thermal fluctuations. The Casimir effect is very general and finds applications in various fields of physics. This review is limited to the rapid progress at the intersection of experiment and theory that has been achieved in the last few years. It includes a critical

Jiankui He, Jun Sun, Michael W. Deem

We investigate the selective forces that promote the emergence of modularity in nature. We demonstrate the spontaneous emergence of modularity in a population of individuals that evolve in a changing environment. We show that the level of modularity correlates with the rapidity and severity of environmental change. The modularity arises as a synergistic resp

Y. S. Kim

It is known that optical activities can perform rotations. It is shown that the rotation, if modulated by attenuations, can perform symmetry operations of Wigner's little group which dictates the internal space-time symmetries of elementary particles.

Adrian A. Budini

In this paper, single-molecule spectroscopy experiments based on continuous laser excitation are characterized through an open quantum system approach. The evolution of the fluorophore system follows from an effective Hamiltonian microscopic dynamic where its characteristic parameters, i.e., its electric dipole, transition frequency, and Rabi frequency, as w

Peter Vereš, Leonard Kornoš, Juraj Tóth

A simulation of de-biased population of NEAs is presented. The numerical integration of modeled orbits reveals geometrical conditions of close approaching NEAs to the Earth. The population with the absolute magnitude up to H=28 is simulated during one year. The probability of possible discoveries of the objects in the Earth vicinity is discussed.

Amit Hogadi, Chenyang Xu

In this note, we discuss the derived functors of infinite products and homotopy limits. $QC(X)$, the category of quasi-coherent sheaves on a Deligne-Mumford stack $X$, usually has the property that the derived functors of product vanish after a finite stage. We use this fact to study the convergence of certain homotopy limits and apply it compare the derived

Gregory S. Ezra, Stephen Wiggins

We study the phase space geometry associated with index 2 saddles of a potential energy surface and its influence on reaction dynamics for $n$ degree-of-freedom (DoF) Hamiltonian systems. For index 1 saddles of potential energy surfaces (the case of classical transition state theory), the existence of a normally hyperbolic invariant manifold (NHIM) of saddle

Brian Karrer, M. E. J. Newman

Directed acyclic graphs are a fundamental class of networks that includes citation networks, food webs, and family trees, among others. Here we define a random graph model for directed acyclic graphs and give solutions for a number of the model's properties, including connection probabilities and component sizes, as well as a fast algorithm for simulatin

John G. Learned

Large liquid scintillation detectors have been generally dedicated to low energy neutrino measurements, in the MeV energy region (as for example, KamLAND and Borexino). Herein we describe the potential employment of large detectors (>1 kiloton) for studies of higher energy neutrinos interactions, from the cosmic rays and as a long baseline neutrino detector.

T. Y. Chen, S. X. Huang, Z. Tesanovic, R. H. Liu

The superconducting gap in FeAs-based superconductor SmFeAs(O1-xFx) (x = 0.15 and 0.30) and the temperature dependence of the sample with x = 0.15 have been measured by Andreev reflection spectroscopy. The intrinsic superconducting gap is independent of contacts while many other "gap-like" features vary appreciably for different contacts. The determi

Magnus Axelsson, Stefan Larsson, Linnea Hjalmarsdotter

We study the soft X-ray variability of Cygnus X-3. By combining data from the All-Sky Monitor and Proportional Counter Array instruments on the RXTE satellite with EXOSAT Medium Energy (ME) detector observations, we are able to analyse the power density spectrum (PDS) of the source from 10^(-9) - 0.1 Hz, thus covering time-scales from seconds to years. As th

T. A. van Kempen, E. F. van Dishoeck, D. M. Salter, M. R. Hogerheijde

The Ophiuchus clouds, in particular L~1688, are an excellent region to study the embedded phases of star formation, due to the relatively large number of protostars. However, the standard method of finding and characterizing embedded young stellar objects (YSOs) through just their infrared spectral slope does not yield a reliable sample. This may affect the

Mukremin Kilic, Piotr M. Kowalski, William T. Reach, Ted von Hippel

We present Spitzer 5-15 micron spectroscopy of one cool white dwarf and 3.6-8 micron photometry of 51 cool white dwarfs with T_eff < 6000 K. The majority of our targets have accurate BVRIJHK photometry and trigonometric parallax measurements available, which enables us to perform a detailed model atmosphere analysis using their optical, near- and mid-infrare

Hanzhong Zhang, J. F. Owens, Enke Wang, Xin-Nian Wang

Within the next-to-leading order (NLO) perturbative QCD (pQCD) parton model, suppression of away-side hadron spectra associated with a high $p_{T}$ photon due to parton energy loss is studied in high-energy heavy-ion collisions. Dictated by the shape of the $γ$-associated jet spectrum in NLO pQCD, hadron spectra at large $z_T=p_T^{h}/p_T^γ \stackrel{>}{\sim}

Aaron C. Boley

I argue for two modes of gas giant planet formation and discuss the conditions under which each mode operates. Gas giant planets at disk radii $r>100$ AU are likely to form in situ by disk instability, while core accretion plus gas capture remains the dominant formation mechanism for $r<100$ AU. During the mass accretion phase, mass loading can push disks to

G. T. Davies, David Gilbank, Karl Glazebrook, Richard Bower

We use a K-selected (22.5 < K_AB < 24.0) sample of dwarf galaxies (8.4 < log(M*/Msun) < 10) at 0.89<z<1.15 in the Chandra Deep Field South (CDFS) to measure their contribution to the global star-formation rate density (SFRD), as inferred from their [OII] flux. By comparing with [OII]-based studies of higher stellar mass galaxies, we robustly measure a turnov

A. Lecavelier des Etangs, A. Vidal-Madjar, J. -M. Desert

Using numerical simulation, Holmstrom et al. (2008) proposed a plausible alternative explanation of the observed Lyman-alpha absorption that was seen during the transit of HD 209458b (Vidal-Madjar et al. 2003). They conclude that radiation pressure alone cannot explain the observations and that a peculiar stellar wind is needed. Here we show that radiation p

Mohamed Louzari, L&#39;moufadal Ben Yakoub

Let $R$ be a ring and $σ$ an endomorphism of $R$. In this note, we study the transfert of the symmetry ($σ$-symmetry) and reversibility ($σ$-reversibility) from $R$ to its skew power series ring $R[[x;σ]]$. Moreover, we study on the relationship between the Baerness, quasi-Baerness and p.p.-property of a ring $R$ and these of the skew power series ring $R[[x

William Arveson

Paul Halmos&#39; work in dilation theory began with a question and its answer: Which operators on a Hilbert space can be extended to normal operators on a larger Hilbert space? The answer is interesting and subtle. The idea of representing operator-theoretic structures in terms of conceptually simpler structures acting on larger Hilbert spaces has become a c

John M. Cannon, John J. Salzer, Jessica L. Rosenberg

We present new optical imaging and spectroscopy and HI spectral line imaging of the dwarf galaxy ADBS 113845+2008 (hereafter ADBS 1138). This metal-poor (Z~30% Z_Sun), &#34;post-starburst&#34; system has one of the most compact stellar distributions known in any galaxy to date (B-band exponential scale length =0.57 kpc). In stark contrast to the compact stel